The proposed research involves an investigation of approaches to the total synthesis of the racemic forms of the antileukemic tricyclic diterpenes jatrophatrione and dolartiol and the tricyclic bromosesquiterpene aplysistatin. The approach to dl-jatrophatrione will involve a Diels-Alder reaction between a cyclopentenone derivative and a pentalene derivative containing a diene moiety to form a 5/5/6/5-fused tetracyclic system. After appropriate manipulation of functionality and stereochemistry, the bond between the B and C rings will be cleaved in order to establish the 5/9/5-fused ring system in the natural product. The approach to dl-dolatriol will involve an aprotic Michael addition of the kinetic enolate of 2-isopropyl-5-methyl-2-cyclopenten-1-one to an alpha-methylene cyclohexanone derivative containing a protected methyl ketone side chain at the Beta-position. Then, the methyl ketone will be deprotected and the product subjected to intramolecular aldol condensation to form the 6/7/5-fused ring system of dolatriol. Appropriate steps will then be followed to complete the carbon skeleton and introduce the three allylic hydroxyl groups of the natural product. The approach to dl-aplysistatin will involve construction of a perhydrobenzoxepanone from which the Gamma-lactone ring and other functionality of the natural product can be elaborated.